Reality TV star Nicole Richie has been diagnosed with hypoglycaemia sparking fears over her health.

Hypoglycaemia means the levels of sugar in Nicole's blood are lower than is needed to keep her body going, meaning she may often feel tired.

Speaking to America's People magazine, a spokesperson for The Simple Life star said: "In her ongoing effort to focus on her wellbeing, Nicole has recently been diagnosed with hypoglycaemia."

However it seems the 25-year-old is receiving medical treatment to help her. "[She] is taking Steps to manage it," the spokesperson added.

Nicole, the adopted daughter of singer Lionel Richie, has constantly denied tabloid speculation that she has an eating disorder, despite being considered to be a size zero by many.

Last October Nicole, the ex-best-friend of Paris Hilton, told the press that she would be visiting a dietician to investigate why she can't put weight on. Only weeks ago, the star also needed medical treatment for dehydration while filming the new series of the Simple Life with the hotel heiress.

The announcement of her diagnosis will No Doubt place the spotlight once again upon the skinny star's health and wellbeing.